0BODMAS is an acronym or mnemonic used to help pupils remember the correct order to complete mathematical calculations in (this called ‘order of operations’). Each letter stands for a mathematical operation, as shown below:
| Brackets | ( ) |
| Orders/Others | Orders are square roots or indices (sometimes called powers or exponents, square numbers and cube numbers). For example, 2³: the little 3 means that you multiply the number 3 times, 2 x 2 x 2 = 8. A square root is the inverse of a square number, so √25, the square root of 25, is 5 because 5 x 5 or 5² equals 25. |
| Division: ÷ | Splitting into equal groups or parts |
| Multiplication: x | Groups of |
| Addition: + | The total of numbers together |
| Subtraction: - | To take away numbers from other numbers |
When you complete a mathematical number sentence involving several different operations then BODMAS helps you to know which order to complete them in.
- Anything in Brackets should be completed first.
- Then the orders.
- Then any division or multiplication.
- Finally addition or subtraction.
If a calculation involving division and multiplication then complete them as they appear from left to right. This is the same for addition and subtraction; they are completed as they appear from left to right.
Examples:
| Calculation | Order of completion | Answer |
| 3 x (7-3) = | Complete the subtraction first because it is in brackets. | 3 x 4 =12 |
| 2 + 3² = | Complete the power first 3² = 3 x 3 = 9 then the addition. | 2 + 9 = 11 |
| 3 x 10 ÷ 2 = | Multiplication and division have the same level of order so complete from left to right. | 30 ÷ 2 = 15 |
| 6 – 2 + 5 = | Addition and subtraction have the same level of order so complete from left to right. | 4 + 5 = 9 |
| 30 – 2 x 5 = | Complete the multiplication first and then the subtraction. | 30 – 10 = 20 |
